Bush was kidding around when he said that, unlike Putin, he has definitely decided to leave office when his term expires. But it came during an interesting exchange about what would happen if Putin decides not to give up his monopoly on power in Russia next year when his final constitutional term ends. Putin said recently that he may become prime minister instead, in effect keeping his tight grip on his reemerging country.

How the next president would deal with Putin would be an interesting question. Bush, at least, has the benefit of a seemingly decent personal relationship with the Russian leader that may at least somewhat temper Putin's anti-American and anti-democratic instincts. The next president will come into office with no rapport with Putin and almost surely will emerge from the campaign having trashed Bush for being too soft on the Kremlin leader.

Just this week, for instance, Sen. John McCain (R-Ariz.) chastised Bush for coddling Putin. Unlike the president, McCain said, "I looked into Putin's eyes and I saw three letters -- a K, a G and a B." He told the Republican Jewish Coalition that he would never have invited Putin to Kennebunkport, Maine, as Bush did, and he said "it's time we got a little tough with Mr. Putin." At the same forum, Sen. Sam Brownback (R-Kan.) listed Putin along with rogue leaders such as Iran's Mahmoud Ahmadinejad and Venezuela's Hugo Chavez, making clear what category he places the Russian leader. On the Democratic side, former senator John Edwards (N.C.) recently co-chaired a task force that chided Bush for his handling of Russia.

The Putin factor raises a broader question. What problems will Bush bequeath his successor? Jennifer Loven of the Associated Press recently wrote an insightful piece noting that Bush has long vowed not to pass on problems to future presidents if he could help it, and yet will end up doing just that. He almost certainly will turn over to his successor an Iraq with at least 100,000 U.S. troops still there. He will hand over a national debt exceeding $6 trillion, entitlement programs that are heading for fiscal trouble, a health care system that does not cover 47 million Americans, an energy crisis with oil probably still over $70 or $80 a barrel and an immigration system that virtually everyone considers broken even if they disagree about how to fix it.

On the other hand, Bush has been trying to take some things off the table by finding ways to institutionalize some of his counterterrorism strategies that have proved controversial. He has already signed legislation governing treatment of detainees and appears on the road to pushing through a compromise on warrantless surveillance that would mean the next president might not have to confront the question. He has said he hoped to close the prison at Guantanamo Bay, Cuba, and find another way to deal with terrorism suspects, but that looks less likely to happen by the time he leaves office.

Perhaps most daunting problem Bush may hand his successor would be Iran. Bush finally seems on track to resolving the standoff with North Korea over its nuclear weapons program as the Stalinist regime so far has been fulfilling its agreement to begin dismantling its program. But the president has made no discernible progress in forcing Iran to give up its uranium enrichment program and it looks unlikely at the moment that he can muster enough international will to impose the tougher sanctions that he is seeking.

Bush was practically apocalyptic in his description yesterday of what would happen should Tehran succeed in obtaining a nuclear bomb. "If you're interested in avoiding World War III, it seems like you ought to be interested in preventing them from [having] the knowledge necessary to make a nuclear weapon," he told reporters. That sort of talk has led to sometimes feverish speculation that Bush would not leave office unless he has dealt definitively with the problem, even if it means using military force. In reality, Bush does not appear anywhere near such a decision at the moment, but what about a year from now if the Iranians have demonstrated even further progress toward enriching weapons-grade uranium?

His potential Republican successors made clear this week that they would not hesitate to order an attack if necessary and, if anything, seemed to be jockeying over who would be toughest on Iran. During the Republican Jewish Coalition forum, former New York mayor Rudy Giuliani said it was "absolutely necessary that we're clear the military option is not off the table" when it comes to Iran. "We've seen what Iran will do with ordinary weapons he told the group during a meeting in Washington. "If I am president of the United States, I guarantee you we will never find out what they will do if they get nuclear weapons because they're not going to get nuclear weapons."

McCain, former Massachusetts governor Mitt Romney and former Tennessee senator Fred Thompson likewise rattled sabers at the event. "The U.S. must make it clear we will not allow Iran to become a nuclear threat," Thompson said. "The military option must never be off the table." Romney said the question confronting presidential candidates would be: "Will you act to stop a nuclear Iran? Let me assure you of one thing -- I will." He added: "Iran has to understand that not only is the military on the table, it is in our hand." The next president, he said, must make clear that "this is not just some far-flung idea that we might act militarily, but instead we are poised and ready to act." Romney made no mention of consulting with lawyers first, as he did during the most recent Republican debate.

McCain, at least, held out hope that it will not come to military force. "I keep praying every night that we will avoid a conflict with Iran," he told the Associated Press. "I don't think it's inevitable that we're in a conflict with Iran. But I certainly see it as one scenario that could -- and I emphasize could -- take place if we are not effective" using diplomacy and sanctions. "I still say there's only one thing worse than military action against Iran and that is a nuclear-armed Iran."

The open question is whether John McCain or any other would-be president will have to confront that choice -- with or without Vladimir Putin's support.